VLSI STRUCTURE OF LOCOS INSULATING REGION OF SANDWICHED POLYSILICON BUFFER HAVING SIDE WALL SEALED BY RECESS AND METHOD FOR FORMING THE SAME

摘要

PURPOSE: To provide an insulating structure of a sandwiched polysilicon buffer, having a sidewall sealed by a recess, in order to prevent an oxide at an edge or corner of a groove upon fabrication of a very large scale integrated(VLSI) circuit having submicron line widths, and also provide a method for forming the structure. ;CONSTITUTION: The method for forming a recessed local-oxidation-of-silicon(LOCOS) insulating region includes a step of forming a first silicon nitride layer 40 between a pad oxide layer 12 and a polysilicon buffer layer 14, and a step of forming a second nitride layer 16 on the polysilicon buffer layer. The method further includes a step of forming a sidewall seal 30 at the periphery of the active groove regions prior to a field oxidization step. Thereafter, an inverted groove region is etched to make a recess therein, and an oxide is grown in the recess. A formed field oxide insulating region 34 is a shallow- recessed field oxide, which has a less corrosive action into the active groove regions.;COPYRIGHT: (C)1995,JPO